a very unusual shaped knotpuzzle, constructed just like a row of columns, look at the name Columnata 2 P3C ( = 2 pieces in 3 columns) a later coming puzzle Pylon is based on the same designidea;
you have to put out the 2 identical pieces out of the columns;

difficulty

solution level: 12.5, also not for real beginners, but very nice to play with it